time.Sleep(backOff(attempt))
			}
		}()
		return true
	}
	return false
}

// MarkOffline - will mark a client as being offline and spawns
// a goroutine that will attempt to reconnect if HealthCheckFn is set.
// returns true if the node changed state from online to offline
func (c *Client) MarkOffline(err error) bool {
	c.Lock()
	c.lastErr = err
	c.lastErrTime = time.Now()

	sys.hMutex.RLock()
	defer sys.hMutex.RUnlock()
	if h, ok := sys.hc[ep.Host]; ok {
		return !h.Online
	}
	go sys.initHC(ep)
	return false
}

// markOffline sets endpoint to offline if network i/o timeout seen.
func (sys *BucketTargetSys) markOffline(ep *url.URL) {
	sys.hMutex.Lock()
	defer sys.hMutex.Unlock()
	if h, ok := sys.hc[ep.Host]; ok {
		h.Online = false
		sys.hc[ep.Host] = h
	}
}